Objective: Classification of patients with low back pain (LBP) into subgroups is important as considerable variability exists in the LBP population. Clinical applicable, reliable, and valid tests to differentiate patients with LBP are therefore necessary. The purpose of this study is to examine the reliability, internal consistency, and clinical importance of 3 clinical tests that analyze motor control mechanisms of the lumbopelvic region in patients with nonspecific LBP.
Methods: Thirty-six patients with chronic nonspecific LBP volunteered for the study (cross-sectional design). The patients were examined by 2 assessors who were blinded to the results of each other. The following tests were performed: the Trendelenburg test, the active straight leg raise (ASLR) test, and the ASLR with visual inspection of the breathing pattern.
Results: The test-retest reliability coefficients (kappa) were greater than 0.75 for the Trendelenburg score and greater than 0.70 for the ASLR. The interobserver reliability coefficients were greater than 0.39 for the assessment of the breathing pattern during the ASLR. The Cronbach alpha coefficient for internal consistency of the Trendelenburg and ASLR tests was greater than .73. No significant associations were found between the outcome of the tests and self-reported pain severity or disability.
Conclusions: These data provide evidence favoring the test-retest reliability of the Trendelenburg and ASLR tests in patients with LBP. The internal consistency of the outcome of these tests was high for both assessors, suggesting that these tests assess the same dimension. The interobserver reliability of the assessment of the breathing pattern was fair to moderate. Further research regarding the interobserver reliability, clinical importance, validity, and responsiveness of the Trendelenburg test, ASLR test, and breathing pattern during these tests is required.